Semileptonic form factors D → π, K and B → π, K from a fine lattice

Deutsches Elektronen-Synchrotron DESY 22603 Hamburg Germany
European Physical Journal A (Impact Factor: 2.74). 01/2009; 43(1). DOI: 10.1140/epja/i2009-10893-3
Source: arXiv


We extract the form factors relevant for semileptonic decays of D and B mesons from a relativistic computation on a fine lattice in the quenched approximation. The lattice spacing is a = 0.04 fm (corresponding to a
-1 = 4.97 GeV), which allows us to run very close to the physical B meson mass, and to reduce the systematic errors associated with the extrapolation in terms of a heavy-quark expansion. For decays of D and Ds mesons, our results for the physical form factors at

$\ensuremath q^2 = 0$
are as follows:

$\ensuremath f_+^{D\rightarrow\pi}(0) = 0.74(6)(4)$

$\ensuremath f_+^{D \rightarrow K}(0) = 0.78(5)(4)$

$\ensuremath f_+^{D_s \rightarrow K} (0) = 0.68(4)(3)$
. Similarly, for B and Bs we find

$\ensuremath f_+^{B\rightarrow\pi}(0) = 0.27(7)(5)$

$\ensuremath f_+^{B\rightarrow K} (0) = 0.32(6)(6)$

$\ensuremath f_+^{B_s\rightarrow K}(0) = 0.23(5)(4)$
. We compare our results with other quenched and unquenched lattice calculations, as well as with light-cone sum rule predictions, finding good agreement.

Download full-text


Available from: Ahmed al-haydari,
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: While the energy of the universe has been established to be about 0.04 baryons, 0.24 dark matter and 0.72 dark energy, the cosmological entropy is almost entirely, about $(1 - 10^{-15})$, from black holes and only $10^{-15}$ from everything else. This identification of all dark matter as black holes is natural in statistical mechanics. Cosmological history of dark matter is discussed. Comment: 6 pages latex. Plenary talk at QTRF-5 Conference, University of Vaxjo, Sweden. June 2009
    07/2009; 1232. DOI:10.1063/1.3431517
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: A discussion of the entropy of the universe leads to the suggestion of very many intermediate-mass black holes between thirty and three hundred thousand solar masses in the halo. It is consistent with observations on wide binaries as well as microlensing and considerations of disk stability that such IMBHs constitute all cold dark matter Comment: 4pp latex. Plenary talk at BSM-LHC conference, Northeastern University, June 2009
    Nuclear Physics B - Proceedings Supplements 07/2009; 200(1). DOI:10.1016/j.nuclphysbps.2010.02.080 · 0.88 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: A brief review of the theoretical description of exclusive and inclusive semileptonic charm decays is given. In light of the recent experimental puzzles in leptonic charm decays, the complementary role of semileptonic modes is emphasized. The relevance of semileptonic charm decay studies to the precise determination of the Vub CKM matrix element from semileptonic B decays is also discussed. Some interesting and important theoretical challenges are mentioned. Comment: 8 pages, 3 figures, talk given at the Charm 2009 workshop, May 20 - 22, 2009, Leimen, Germany
Show more